Perhaps you should try some spelling variations:
thong xuong » khong xuong, thong duong, thong huong
hanh trinh » canh tranh, hanh chinh
hieu nganh » vien nganh, hieu manh, nghiep nganh
hiem ngan » kim ngan, viem gan
trinh tai » trinh toan, trinh tu, trinh han
tai thong » tai thuong, tai phong, tai trong
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu nganh) OR (hiem ngan)) - hanh trinh tai thong xuong ((dan toan) or (dan than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu nganh) OR (hiem ngan)) - hanh trinh tai thong xuong ((dan toan) OR (dan than)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu nganh) OR (hiem ngan)) - hanh trinh tai thong xuong ((dan toan) or (dan than)) cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu nganh) OR (hiem ngan)) - hanh trinh tai thong xuong ((dan toan) or (dan than)) cao*.